Apparatus for transmitting coded currents



March 8 .n A. J. soRENsl-:N

APPARATUS FOR TRANSMITTING CODED CURRENTS Filed Jan. 29, 1926 BY Q A 2/` ATTORNEY r desired manner.

Patented S, 1927.

NETE-l) "STATES PATENT OFFICE,

ANDREW J'. SORENSEN, OF WLKINSBURG, PENNSYLVANIA, ASSIGNOR T0 THE UNION SNITCH @c SIGNAL COMPANY, GF SW'SS'VALE, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

APPARATUS FOR TRANSMITTING CODED CURRENTS.

Application lecl January 29, 1926. Serial No. 84,592.

My invention relates to apparatus for transmitting coded currents. Apparatus embodying my invention is particularly suitable for, though in no way limited to, automatic train control systems, in which systems the Ytransmitting apparatus is used to supply the coded currents to the rails of the trackway.

I will vdescribe one form of transmitting apparatus embodying my invention, and will then point out the novel features thereof in claims.

The accompanying drawingis a diagrammatic view illustrating one form oftransinitting apparatus embodying my invention.

Referring to this drawing, the reference characters 1 and 1 designate the track rails of a stretch of railway track. A portion of this stretch is divided, by means of insulated joints, to form a track section M-N. A track relay R is connected across the rails adjacent one end of the section MN and may be used to control traffic governing apparatus not shown inthe drawing, in any The code transmitting apparatus comprises a series of slow acting relays, here shown as three in number, A, B and C. These relays are controlled by a circuit controller K which will usually be controlled in actual practice in accordance with traffic conditions. open, relays A, B and C are all de-energizedf ldlhen circuit controller K is closed, however, current flows from a suitable source of energy, such as a battery G, through wire 9, circuit controller K, wires 10and 11, winding of relay A, wire 12, back contact 13 of relay C and wire 14, back to battery Cr. Relay A therefore becomes energized and closes its front contacts. The closing of front contact 17 of relay Acompletes the circuit for relay B which circuit is from battery G, through wire 9, circult controller K, wires 10, 15, and 16, front contact 17 yof relay A, wire 18, winding of relay B, and wires 19 and 14, back to battery G. Relay B therefore becomes energized and closes a circuit for relay C which may be traced from battery G, through wire 9, circuit controller K, wires 10, 15 and 20, front contact 21 of relay B, wire 22, winding of relay C and wires 23 and 14 back to battery G.

Then circuit controller K is` When relay C becomes ener-v gized, back contact 18 thereon opens the circuit for relay A. Relay A then opens its front contact 17 so that relay B becomes deenergized, and when relay B opens its front contacts 21, relay C becomes de-energized, thereby re-closing back contact 13 of relay C and re-establishing the circuit for relay A. It will be plain from the foregoing that when circuit controller K is closed, relays A, B and C are repeatedly energized and deenergized in cascade.

The slow acting relays A, B and C may have any desired characteristics. For example, I will assume that the relays shown in the drawing are constructed to have quick pick-up and slow release. Thus, relay A may require yone-fourth second following cle-energization of the relay, before the relay opens. Similarly, the time of release of relay B may be one second and the time of release of relay C may be one-half second. The relays each require only a small fraction of a second for pick-ug and the time required for all three relays to pick up in succession is about one-fourth second. The total time of a complete cycle of operation, that is, the time required for all the relays to become successively energized and cle-energized, is therefore about two seconds.

Current is supplied to the rails of section M N from a suitable source of energy, here shown as a transformer D comprising a secondary and a primary 51 constantly supplied with alternating current from a` source not shown in the drawing. The secondary 50 of transformer'D is at times connected with the rails of the section, by means described hereinafter, over suitable contacts or combinations of contacts on relays A, B and C.

The reference character S designates a selector comprising a movable lever 3 and a plurality of fixed contacts 4, 5, 6, 7, and 8, arranged to be separately engaged by the lever 3. When selector S is open, as shown in the drawing, secondary 5() of transformer D is disconnected from rail 1 of section lift-N. When contact 3-4 of selector S is closed, a circuit is established from secondary 50 of transformer D, through wires 29 and 30, front contact 28 of relay C, wires 31, 32 and 38, front contact 24--24a of relay A, wire S4, contact 3-4 of selector S, and wire 35 to rail 1 of section M-eN, and from rail la of section M-N- througlr Wire Sback to secondary 50. It will be seen'tlierefore'that when contact 3-4 of selector S is closed, cur-rent is supplied toY rails l and la from transformer D only when relays A and C are both closed. In order to explain the 0peration of the apparatus when selector contact 3-4 is closed, Il will assume that relays A, B and C are all open, as When circuit controller K is open. Underthis condition contacts 28 and 24u-24 are both open and no current is supplied to the t-rack rails. I will next assume that circuit controller K becomes closed. Relay A then becomes energized, closing front Contact 2li-24a, but the circuit' forsecondary 50 is still open atv front contact 28 of relay C. Relay B picks up almost immediately, however, and relay C then picks up. rlie time required `for all three relays to pick up in succession is about one-fourthl second. Then front contact 2S of relay C closes, the circuit for secondary Ofis closed; and current is supplied to the track' rails from transformer D. The closingjof relay C interrupts the circuit for relay A however as hereinbefore explained and relay A commences to open. Relay A requires one-fourth second to open its front contacts after the relay is cle-energized, hoW- ever, and duringpthis time interval current is supplied to the track rails. l/Vhen relay A opens, the circuit for secondary 50 is opened Vat front contact 24-24La. At the same time the circuit for relay B is opened, and after one second relay B opens. At the expiration ot one-half second after the openingl of relay B, relay C opens, thereby returning the apparatus to its original condition. It follows vthat as long as relays A, B and C are operated, and Contact 3 4 of selector S is closed, the rails Will be supplied with impulses ot current of about one-fourth second duration separated by intervals ot' about one and three-quarter seconds during whichv no current is supplied tothe track- Way. Current supplied to the trackway in the manner just described will be termed code-I. f

Similarly, when contact of selector S is closed; a circuit is completed for secondary 50 including the rails lY and la of section lvl-N over back contact 26 of relay B and front contact 28 of relay C. Then this circuit is closed and circuit controller K is closed to operate relays A, B and C, current is sup-plied t0 the trackway according to code II, and the rails will then be supplied with impulses of current of about onelia-lf second duration, separated by time intervals' of about one and one-half seconds during which no current Will flow in the track rails. In similar manner when contact 3 6' of selector VS is closed, secondary 50' is connected with the trackway over back 4Contact 25 of relay A and front contact 27 of relay B; when contacts` 3 7 of selector S areclosed secondary 50 is-connected'with the trackivay over back contact 24-241 of relay A and front contact 28 of relay C; andWhen Contact. 3-8 of selector S is closed,.ra circ-uit is established for secondary 50 including the rails of the section M-N and front contact of about one-'fourth second during Whicl'rno current is supplied to the trackway.

One advantage of the transmitting apparatus embodying my invention from other forms of apparatus hitherto suggested is that the time intervals are measured by slow releasing relays which are standard pieces of apparatus and are extremely reliable in operation.

Although I have, forpurposes-ot explanation, stated speciiic values :tor ,theV time intervals of the various codes and for the characteristics of the timing relays A, B and C, it shouldv be particularly pointed out that my invention is not limited' to these specific values.

It should also be understood, that although I have here illustrated the transmitting apparatus supplying coded currents. to the rails of a section of railwayv track, the currents might equally Welll be supplied t0 any other conductor;

The coded currents supplied t0=V the track- Y Way by means ot the transmitting apparatus which I have described hereinbefore, may beV used in any suitable manner such as to control traffic governing means which form no part of my present invention and Which are omitted from the drawing for the sake of simplicity.

Although I have herein shown and described only one form of transmitting apparatus embodying my invention, it is understood that various changes and modifications may be made therein Within the scope ot the appended claims Withoutfd'eparting vvfrom the spirit and scope of'my invention.

Having thus described myV invention, what I claim is:

l. In combination with a stretch of railway track` a series of relays operating in cascade, a source of current, and means for connecting saidl source with at least one rail of said section in series with a contactV on at least one of said relays.

2. In combination With a conductor, a series of slow acting relays, means for repeatedly energizing and demenergizing said relays in cascade,- a source of current, and

means for at times connecting said source with said conductor over contacts on certain of said relays.

3. In combination with a conductor, a series of slow acting relays, means for repeatedly energizing and cle-energizing said relays in cascade, a source of current, and a s-elector for connecting said source with said conductor over contacts on selected ones of said relays.

4. In combination with a stretch o't' railway track, a series of slow releasing relays, means for repeatedly energizing and vdeenergizing said relays in cascade, a source of current, a selector, and a plurality of circuits controlled by said selector and all including at least one rail of said stretch and each including ditl'erent contacts or combinations of contacts on said relay.

5. In combination with a stretch ot railway track, a series of slow releasing relays, means for repeatedly energizing and deenergizing said relays in cascade, a source of current having one terminal constantly connected With one rail of said stretch, and

a selector for connecting the remaining terminal of said source with the other rail of said stretch through selected contacts ot said relays.

6. In combination With a stretch of railway track, a series of slouv acting relays, a circuit for each said relay except the lirst controlled by the preceding relay in the series, a circuit for said lirst relay controlled by the last relay of the series, and means controlled by said relays for supplying` coded current to the rails of said stretch.

7. In combination with a stretch ot railway track, a series of slow releasing relays, .a circuit for the lirstrelay ot said seri-es inclu-ding a back contact ot' the last relay of the series, a circuit for each of the remaining relays including a front contact of the preceding relay in the series, and means controlled by said relays for supplying coded current to the rails of said stretch.

In testimony whereof I aiiix my signature.

ANDREl/V J. SORENSEN.

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